Steam-boiler furnace and method of operating the same



H. C. HEATON.

STEAM BOILER FURNACE AND'METHOD 0F OPERATINQTHE SAME.

APPLICATION FILED MAY 24, 1917.

1 1 r v Patented Dec. 27, 1921.-

a sHgETs-HEET 1.

mt a

H. C HEATON.

STEAM BOILER FURNACE AND METHOD OFOPERAHNG THE SAME.

APPLICATION FILED MAv24, 1917.

1,401,253. Patented Dec. 27, 1921 3 SHEETSLSHEET 2.

m NTOR. MM 5 m,

w ATTORNEYS.

H. c. HEATON. SlEAM BOILER FURNACE AND METHOD OF OPERATING THE SAME.

APPLICATION FILED MAY 24, 19H- 1,40 1,253, Patented Deu.27, 1921.

3 SHEETS-SHEET 3- YMfl/IQVENTOR. BY na A TTORNEYS.

UNITED STAT$ Application filed May 24,

To all ill/lam vie may concern:

e it knowrrthat I, HERMAN (I. Harrow, a citizen or the United States,residing. at Berwyn, in the county of Cook, State of Illinois, haveinvented certain new and useful Improvements in Steam-Boiler Furnacesand Methods of Operating the Same,

; of which the following-is a specification.

1y invention relates to a furnace. arrangement for steam boilers andmethod of operating the same in WlllCll PI'UVISlUll 1s made forconveying'unconsumed fuel and ash from an, underfeed stoker toward therear of the furnace chamber and there discharg ing the residue into ahopper. The present application is a continuation in part of myapplication Serial No. 16,538, liled March 24, 1915, for steamgenerators, [Patent Xe. 1,242,438 issued Oct. 9, 1917.

In'the accompanying drawings Figure 1 is a side elevation of one type ofboiler containing the present improvement, certain parts in section;Fig, 2, a transverse section on the plane of the line 2--2 of Fig. 1;and Fig. 3, a view similar to Fig. 1, showing -a modified form ofconveyer with another type ofboiler. Similar reference numerals indicatesimilar rarts the several views.

Referring to Pig. 1, the numeral 1 indicatcs a bank of horizontallyinclined generating tubes connected to front and rear headers 2 and 3.These headers are connectedby tubes to steam and water drums 4. \Vithinthe bank of tubes are longitudiarranged as shown in Fig. 2 furnace gasesacross the't'ubes, abovethe tubes and thence to the stack 6. 1n thetriangular space be tween the. bank of tubes and the steam and waterdrums isan'econemizer 7, a feed pipe. 8 leads from the economizer to thesteam and water drama I For ,the' purpose of illustrating my inwention,I have shown, more or less diagrammatically, a Taylor underfeed stoker,although any other type of unclerfeed stoker may be employed. AS shown,this comprises a series of retorts 9, all of which are connected to ahopper or hoppers 10. In

to direct the. in the space each retort 'is a reciprocating plungerwhich pushes the fuel nto the furnace. Between Specification of LettersIfatent.

. tend from near the lower being broken awayand others PATENT OFFICE.

Patented nee. 27, 1921.

1917. Serial No. 170,611.

the rctor'l's are air boxes 11 from which air is delivered underpressure into the fuel pit through twyers 12. In Fig. 1, the frontJlurnacc wall 13 is shown as racked over inwardly. liclow thgunderleedstoker and in position toreceive the' unconsumed fuel and ash therefromis aneilflless oonveyer 14, the constructimi of whichfnlay be similar tothat oi a chain grate stoker. It comprises a frame supported on wheels15 adaoted to travel on a trackway and to be moved into and out oi thefurnace. The conveyor 14 may be of any well-known construction in whichthe grate surface is caused to travel around sprocket wheels 16 one ofwhich is driven either tiuuously by suitable means and the conv'eyer 1spreferably of such length as to exend of the underteed stoker to therear oi? thejeombustion chamber. The unconsumed fuel and ash from theunderfeed stoker aredelivered to the conveyor 14. or chain grate stokerwhich latter is periodically or continuously advanced in order to feedtoward the rear the material received by it and to discharge the residueat the rear. During the travel of the chain grate, combustible elementsin the partly consumed fuel will be burned, the gases passing minglingwith those from the fuel on the underieed stoker. At the reanof thecombustion chamber is a bridge wall 17 protected by a water box 18, thedischarge material falling over the rear of the grate and beingdischarged into a hopper 19.

The chain grate Stoker 14 may be with drawn -froni tlleiurnaee chamber,when desired, into a passageway below the furnace floor. This passagewaymay be normally closed by a hinged door 20.

In Fig. 3, have shown the type of B & \V boiler, comprising a bank ofinclined generating tubes 21 expanded into frontaud rear headers, whichlatter are connected, as usual, toa steam and. water drum 22. In themodification here shown, the grate- 23 is materally shorter than thatshown. in Fig. 1, and vision made .for moving it from the furnacechamber. 'In this form the grate is standard supported on sprocketWheels 24, one of intermittently or coni the chain grate.

which is driven by suitable means and. as in r 1g..1, the ash and fuelrefuse are delivered front-the lower end of. the underfeed stoker to thet'aveling g ate and by the latter the residue is carried to the rear 'ofthe furnace chamber and discharged into a hopper :25. bridge all :26 atthe rear of the combustion chamber projects over the rear of This wallis protected by a 'water box 27 connected with the boiler circulationthrough the pipesZ-S and .29.

l\s is well-known, the fuel supporting surface of the underfeedStokerillustrated in the drawings is inclined, and the fuel and ash aregradually moved to the lower end thereof. From. this point they aredischarged upon the horizontal surface of the traveling grate by whichthey areconveved through the furnace. As they are so conveyedv anyunconsumed combustible elements in the fuel will be burned, therebyeffecting an economy in the operation of furnaces fired by an underfeedstoker. The

arrangement described does away with the use of dumping plates. clinkergrinders and other similar devices as heretofore generally used withunderfeed stokers.

The underfeed stoker combined with the chain grate stoker gives betterresults and higher efficiencies than would be secured through the use ofother types of stokers combined with the chain grate stoker.

An uuderfeed stoker is supplied with a forced blast, and the amount ofcoal burned on the underfeed stoker can be regulated independently'ofthe suction within thefurnace chamber. The suction within the furnacechamber can, therefore. be made such as is best adapted for burning thecoal on the chain grate Stoker, and both the chain grate stoker and the.underfeed stoker can be operated at their maximum elliciencies. Shouldany other stoker than the underfeed be used where a forced draft is notavailable, and the coal from the other type of stolcer fed to the chaingrate stoker, the amount of furnace draft required for the other type ofstoker would be. considerably more than that required for burning thepartly spent coal on the chain grate stoker, and the result would bethat a great amount of excess air would pass into the fup nace throughthe coal on the chain grate s oker and unccouomical results would besecured. The combination disclosed in the application is, therefore.one'that can be operated at higher elliciencies than would be obtainedwith other forms of stokers combined with the chain grate.

hat. I claim and desire to secure by Let tors latent of the UnitedStates is l. A fuel burning method comprising forcibly underfceding fuelinto-the front portion of bed of burning fuel and therebc vond bodilycarrying along the fuel bed derfeed stokeand a forced air blast, and aso 4.. A steam boiler furnace having an un-' travelin chain grate at therear of the.

stoker, the. Stoker being arranged to feed fuel and ash-upon thetraveling chain grate.

5.-In a boiler furnace the combination with an underfeed stoker having aforced air blast. of a movable grate u )on which the fuel and ash aredischargec, said grate being arranged to convey the residue to the rearof the furnace, a bridge wall at the rear of said chamber. and a'ater-box for pro? tecting said wall. the discharge of the ashes beingthrough the. space between the grate and the said water-box.

derfeed stoker and a forced air blast, an end-- less refuse removingdevice at the rear of the stoker, and connections for. continuously.aetuating 'said endless refuse removing deyice to discharge the residuesfed thereto by the stoker. I

7. A steam boiler furnace having a com bustion chamber, an underfeedStoker Idis posed at the front of said combustion chitinber. and at'aveling chain grate disposed at the rear of said chamber andconstructed and arranged to receive fuel and ash from the underfeedstoker in one portion thereof and discharge the refuse from anotherportion thereof.-

S. A steam boiler furnace having an un-' derfeed stoker and a forced airblast, and a. traveling chain grate at the rear of the stoker, thestoker being arranged to feed fuel .and ash upon the traveling chaingrate, said chain grate having an air supply separate from that of saidunderfeed stoker.

9. 111 a boiler furnace. the combination with an underfeed stoker havinga forced air blast. of a mo 'able grate upon which the fuel and ashfronrsaid stoker are discharged, said grate being arranged to convey theresidue to the rear of said furnace and having an air supply separatefrom that of said 'underfeed stokerm r 10. In a boiler furnace, thecombination with an underfeed stoker having an inclined 'bed and aforced air blas of a movable grate extending rearwardly from said i 6. Asteamboiler furnace having an 'un-.

stoksr and having a substantially hd 'izontal signed my name in tilepresene of two subsuruce lliponi wglchhthe (flueland ash from scribingwitnesses.

sai st0,'er are isc arge said grate being 1 1 1 arranged tb convey thersidue to the rear HhRMAN HEATON' 6 of furnace; andhaving an air supplyWitnesses;

k so I ize fl'om thmfi of said gnderfeed stoken AmYs NEVELING,

testimony whereof have hereunto v A. B. CLARK.

